The present invention relates to a bucket elevator and more particularly to the design of a bucket for use on a bucket elevator.
Bucket type elevators or conveyors are known for various applications, in particular for elevating particulate materials from one location to another. The general construction of a bucket elevator includes an endless belt rotatably supported about a series of pulleys so that the belt includes straight sections extending between the pulleys and curved sections wrapping about the pulleys at any given time. Typical buckets supported on these types of elevators generally comprise a container having an open top end and a flat back wall supported directly adjacent the belt. As the belt is rotated from the curved sections to the straight sections, varying amounts of the back wall of each bucket comes into contact with the belt causing the material being conveyed to be caught therebetween causing contamination when different materials are later conveyed or cause the materials to be crushed or otherwise degraded.
U.S. Pat. No. 4,770,288 to Kruger, U.S. Pat. No. 352,077 to Avery and U.S. Pat. No. 746,486 to Flock disclose variations to elevator buckets, but none provide a satisfactory solution to preventing materials from being trapped between the back wall of the buckets and the belt in a simple and cost effective construction. Kruger requires a complex construction including pivots which require maintenance, while Avery discloses a complex mounting configuration resulting in a shelf being produced between the bucket and the belt which readily traps material thereon causing contamination. Flock requires that the back wall of the bucket itself be formed to space the bucket from the belt, however in this configuration the resulting channels formed readily trap material at the edges thereof between the bucket and the belt as channels formed within the bucket itself do not provide sufficient space between the bucket and the belt.
According to one aspect of the invention there is provided a bucket for a bucket elevator including an endless belt for supporting the bucket thereon, the bucket comprising:
a back wall, a front wall spaced from the back wall, a bottom joining the front and back wall at a bottom side of the bucket and a pair of side walls extending between the front and back wall at spaced positions to form a container having an open top end;
a plurality of spacer elements protruding from the back wall, the back wall including a plurality of mounting apertures in alignment with and extending through respective spacer elements for receiving fasteners to mount the bucket on the belt.
According to a second aspect of the present invention there is provided a bucket elevator comprising an endless belt rotatably supported on a support frame, the belt having a plurality of mounting apertures therein for supporting a plurality of buckets on the belt, each bucket comprising:
a back wall, a front wall spaced from the back wall, a bottom joining the front and back wall at a bottom side of the bucket and a pair of side walls extending between the front and back wall at spaced positions to form a container having an open top end; and
a plurality of spacer elements protruding from the back wall;
the back wall including a plurality of mounting apertures in alignment with and extending through respective spacer elements;
a plurality of fasteners being received through respective mounting apertures in the spacer elements of each bucket and the belt to mount the bucket on the belt.
The use of spacers projecting from the back wall and which include mounting apertures through the spacer elements and the back wall itself provides a bucket of simple construction which is readily installed using common fasteners while providing sufficient spacing between the bucket and the belt. The configuration of the spacer elements readily permits the buckets to be integrally moulded to further simplify construction thereof.
The spacer elements may be integrally formed on the back wall of the respective bucket and are preferably integrally molded with the walls of the bucket out of plastic material.
The plurality of spacer elements preferably includes spacer elements which are spaced both vertically and horizontally from one another on the respective bucket.
The plurality of mounting apertures are preferably only located in spacer elements adjacent the open top end of each bucket to permit the lower spacer elements to be freely displaced away from the belt and release particulate material which may be trapped therebetween.
In one embodiment, the spacer elements may comprise a circular disc such that each spacer element includes a sloped upper surface which is generally convex.
The spacer elements may also be tapered so as to be reduced in cross sectional in a longitudinal direction projecting outwardly from the back wall of the respective bucket.